Technical Marman V band exhaust connections Wow, leak free v bands

5" in the heavy truck world.

 

Got a package in the mail today and I’m impressed with the quality of these Marman exhaust joints.
They came with Remflex type sealing rings for insuring a truely leak free joint.
Perfect.
My weekend is set

 

I have van Jen Wiggins type on/for my 48 diamond t they use clamp/band/ o ring . But have used marmon on aircraft for over fifty years, and on aircraft the must be leak checked, no leak allowed, the pressure on aircraft is a multiple of your exhaust. We use a paste wax on sealing surface for lube, to allow for a leak free assembly.

 

V-Band clamps work best if you sneak up on the final torque.
Meaning, do an initial low torque then lightly tap around the outside diameter. What you will see is the torque you just applied will be diminished.
Re-torque again, then lightly tap again around the outside diameter. Do this several times. This will create a good fit of the mating parts as well as a good even torque.
If you simply install the V-Band clamp and tighten the shit out of it, it will surely leak

 

Tried all that and no dice they still leaked. no way you could get them to not leak.

They will be in the scrap bin soon and the Marman joints will be in place.
A far superior design and function.

 

I am the manufacturer of the Marman flanges and I hope that "Blue one" can get back to this thread to let us all know how the flanges worked!

If anyone is interested in them, go to gbemandrel.com or call us at 503.344.4149

 

I'm just assembling the car now so I will update when it comes time to run.

So far so good, they fit very nicely.

 

First produced by Zeppo Marx by his company Marman... Yes, THAT Zeppo Marx.

 

That’s how you do it! Used several kinds over the years, I always used sealer on the joints, made sure they were aligned, lubed the clamp, tighten, tap, tighten tap, etc. Never had any leaks.

Bones

 

I remember those v band clamps, big ones are used to secure the air inlets on GE-T701 turboshaft engines. Good stuff.

 

I have only seen the v-band ones leak when there was no tube overlap.

 

Shit, you guys have have got me worried. I've got a bunch of stainless V band clamps in my '32 project, and the exhaust is complex and would be a nightmare to rework, and I don't want leaks! One difference however is that the v bands I've used are the precision machined male / female type, so they self align and you can tell when they're snugged up. The interlocking flanges I'd hope help provide a mechanical type seal. Well that's the theory! Anyone have any experience of these type of v bands?

Chris

 

There is no issue at all with the stainless V-band flanges. You keep them clamped together when welding and don’t pound heat into them. I’ve welded up quite a few of them and have 6 on my current project that don’t leak.